Pentax & Nikon - Image Quality

I am someone with a decent, basic understanding of digital photography...but I'd really like to learn more. My first step is to purchase my first dslr. I've had the opportunity to play with a Pentax K-x, K-r, a Sony a300, and a Nikon d7000, and really like the feel of the Pentax cameras. Initially, most of my photos will be for work, shooting interiors for some design work that I do, but I'd also love to learn macro.

Here's the rub...when I look at photos online (Flickr, for example) the Nikon shots just look a bit different than the photos from Pentax cameras. The Pentax photos look very clean and natural, but the Nikon photos look more detailed (especially the macros), with what I can only describe as more subtlety.

Is my impression accurate? I love to hear from someone who's owned both brands of cameras for some first-hand feedback.

Thanks...